Synth Basics

Week 6: Synth Basics -- Compare the graphical interface of four different synthesizers. Clearly show where the Oscillator, Filter, Amplifier, Envelope, and LFO sections are.

One can find many VST synthesizers on the Internet to download. Many of these have a unique graphic interface where all the effects can be set, but it is a bit time-consuming for one to find out what a single synth is capable of. Modular design is a common feature: on almost every interface you can find an Oscillator (OSC or VCO), a Filter (FLT or VCF), an Amplifier (AMP or VCA) with an Amplitude Envelope (ENV), a Low Frequency Oscillator (LFO), and often additional Effects (FX). ('VC' stands for 'Voltage Controlled' in the beforementioned abbreviations.)

On the following figures you can find the graphic interface of four synthesizers with the different modules marked with different colours. In general these interfaces look like real hardware as they have a bunch of knobs and buttons and faders to fiddle with, but unlike most real hardware they often have little screens to show how the waveform looks like, just like an oscilloscope. Some of them even have detachable wires to connect different modules, so one you can redefine the order of these modules and so alter the behaviour of the synth.

Fig.1: Artphase 1.5

Fig.2: Linplug's Free Alpha 3

Fig.3: OdO's Purple 2

Fig.4: Additive Table Synth

Source: http://lesitedeburnie.free.fr

On this site there is a list (under the practical name 'The List') where you can find many free synthesizers to download. You should give them a try if you are interested.

Equalization Basics

Week 5: Equalization Basics -- Demonstrate the configuring of an EQ plugin to function like a large format mixing console EQ section. Include instructions showing how to save the setting as a preset in your DAW.

Whenever you have an audio recording of decent quality, you'll still want to adjust its timbre to fit in your mix. One way to do this is using an Equalizer (EQ) plugin in your DAW.

Contemporary mixing boards (even the smallest ones) tend to have a separate EQ section for each channel, which you can customize its sound with. The bare minimum is a Low Level and a High Level controller, but another one for Middle Level is also common. Larger mixing consoles have separate knobs for Low Mids and High Mids. In most of this cases there are additional controllers to adjust the center frequency of the beformentioned two knobs. Often there is a two-state button in the beginning of the EQ section which you can cut the sub-bass frequencies with.

When you start equalizing your recordings in a DAW, you'll want to set it up in a way you can easily adjust the main frequency bands. For this you should make a preset based on an EQ section of a real mixing board, because they are made for being wieldy and efficient. Remember to use the smallest number of EQ bands you can to save computing capacity.

Fig.1: EQ preset based on an EQ section of a mixing board

The first thing to set up is a High Pass Filter around 60-80Hz. This will help you getting rid of wind rumble, footsteps and the 50/60Hz hum of an occasional ground loop. (However, do not use this when you're mixing sounds of explosions and sub-bass instruments.) Often you can set the gradient of the filter - the steeper the curve is, the more precise adjustment can be made in the frequency domain.

The next one should be a Low Shelf Filter with which you can emphasize the bass frequencies around 80-100Hz you've accidentally lost in the previous step. Another shelf filter should be a High Shelf Filter around 10-12kHz which you can brighten your mix with.

Between these two shelf filters you can always add several Normal Filters (or Bell Filters) to emphasize or suppress definite frequency bands. You can adjust their center frequency and Q factor (real mixing boards lack the latter) besides their level, so you can even cut a disturbing single frequency boost with them. Setting one around 400Hz and another around 2kHz makes a good starting point.

After all you'll want to save your settings to a brand new preset. You'll certainly find a Save or Save Preset button (often under the File menu or an icon of a disc) on the upper part of the plugin window, where you can give it a good name you will find next time as well (e.g. Mixing Board Preset).

Reducing Noise

Week 4: Reducing Noise -- Demonstrate how to reduce unwanted electrical and acoustical noise when recording.

It may be common sense, but avoiding noise during music production is of high priority. Most of the time you will want to make recordings in which only the instrument or the vocals can be heard. If you happen to be somewhere where the acoustics of the environment are worth recording (e.g. grand reverberations of a church, woodnotes and birdsongs of a forest), you should take care of recording it well -- otherwise, you'll want to get rid of echoes and background noises.

During pre-production you should make preparations, because with a few simple steps you can set up such a system which you can keep your recordings nice and clean with. First of all: turn every disturbing appliances off (such as television or air conditioner), be quiet and listen. Once you get used to the silence, you will find some quieter noise sources which can still be disturbing during a recording (fans of your computer, fridge in the kitchen, dogs barking outside, clocks ticking etc.). Move away from them if you can, or isolate the space which you are recording in. Turn the cooling of your computer down a bit (or clean the fans from dust), or even take it to another room; close the door to keep the noises of your household out; close the window, or simply choose a period of time when your neighbourhood is quite silent and you won't disturb them either (e.g. during working hours).

After you've taken care of acoustic noises, you also should take care of electrical ones. If you have the chance, use high quality equipment. Appliances and instruments of global brands are more expensive, but they tend to be of better quality and reliability. Shielded cables, reliable plugs and sockets, not the cheapest power supply units -- all these things can keep you away from electrical noise. There are less financially demanding methods as well: the shorter cables and the fewer pieces of gear you use, the less electrical noise you will find in your recordings. Turn off the dimmers and appliances you do not use, and use balanced cables wherever you can. Also try to avoid ground loop, which generates a disturbing hum of 50 or 60Hz (it depends on the power line frequency in your country).

After having your recording environment arranged carefully, you can start the production stage. If you happen to have a number of different types of microphones, you should consider using a directional one to isolate the instrument or vocalist from the environment. Directing a cardioid mic to the instrument and moving her closer to the sound source are excellent ways to have more direct sound and less background noise in your recordings. By this way you can also keep the signal level quite high, so you can keep the gain on a moderate level and thus keep electrical and background noises low.

During post-production you still have the chance to fix some noise issues, but you'll want to avoid that as much as you can, as they tend to be destructive or they consume way more time than proper preparations. Using a noise gate can keep background noises out, but by this way you'll lose all the lovely nuances such as the sound of the fingers sliding on the strings of an instrument. A long note fading out can also dissolve slowly in noise, and a gate can't do anything to save it. There are restoration effects such as de-noisers or de-hissers, but the processed audio does not sound perfect at all, since it loses its original timbre during the heavy filtering of the process. Prevention is better than cure.

Effects Basics

Week 3: Categories of Effects -- Teach the effect categories including which plugins go in each category and which property of sound each category relates to.

Using various effect plugins is a really fun thing to do, as you can alter the sound of any previously recorded audio to make it sound better, more exciting, or to suit any weird needs of your project. There are analogue and digital effects as well; here we're focusing on the digital ones, because nowadays Digital Signal Processing (DSP) is a thing any computer is capable of, but if you want to use analogue effects, you'll have to purchase them one by one, and these pieces of hardware can be pretty expensive.

The main purpose of the effects is the same: to alter the sound; but their methods can be really different. One can categorize the audio effects in many ways, e.g. like this:

• Dynamic Effects: they alter the amplitude of the audio. A Compressor (surprise!) compresses the sound, as it amplifies the loudest parts less than the others, so the volume will be more balanced, while the dynamics of the audio will be reduced. A Limiter is a really hard Compressor, as it doesn't even let the loudest parts exceed a given volume, however, heavy limiting can distort the sound. An Expander is the opposite of a Compressor, as it expands the dynamics of the audio making the quiet parts quieter and the loud parts louder. A Gate is a tool to mute ("lock out") some parts of the audio, so a Noise Gate can suppress the quieter parts completely (e.g. background noise) but won't do anything to the actual sound.
• Delay Effects: they alter the propagation of the audio. A Delay gives echoes to the audio, so any sound can appear again and again and again and again and again, causing feedback or fading out slowly. A Reverb puts the listener into a given sound environment with many echoes of different delay times and volumes and filters, so one can perceive the sound as being reflected from the walls and other surfaces of a bathroom, a hall, a church or even an arena. A Phaser, a Flanger or a Chorus also operates with delays and filters, producing sounds that are hard to describe but easy to recognize. (These three can also be categorized as Modulation Effects.)
• Filter Effects: they alter the timbre of the audio. A High Pass Filter lets the highs through unaltered but suppresses the lows, a Low Pass Filter makes the opposite, and a Band Pass Filter only lets through the sound between given frequencies (i.e. in a given frequency band). An Equalizer (EQ) lets you set your filters in any way you want to, using parameters (gain, frequency, Q factor, gradient, filter type) or a graphic interface (only gain for the given frequency bands).

I think one always has to hear an effect to find out what exactly it does, so I made a short audio clip using the following effects: Compressor, Delay, Reverb, Phaser, Flanger, Chorus, High Pass, Low Pass, Band Pass, respectively.